1. Field of the Invention
The purpose of this invention is to provide 1) impregnated wood materials introducing a fire retardant property to wood products, 2) impregnation of other cellulosic materials, such as paper and cloth, and other organic compounds in such a way as to allow their intended functions while reducing the risk of flammability, 3) impregnated wood materials introducing increased strength to wood products, and 4) impregnated wood materials introducing decreased solubility of the constituents of the final product thereby providing moisture and leachate and weather resistant products 5) incorporation of a great variety of substances into cellulosic materials to impart a wide range of new properties including strength, flexibility, durability, elasticity, colors, and great resistance to heat.
2. Description of Related Art
In my studies of fire retardants, I became interested in introducing sodium silicate and other fire retardant chemicals into flammable materials in such a way as to make the materials highly fire retardant but also resistant to the effects of weathering and leaching. The use of heat and other techniques to accelerated the polymerization of sodium silicate so as to greatly decrease the water solubility of sodium silicate and any other substances that may be incorporated into the sodium silicate matrix is described in patent application Ser. No. 08/843,160, filed Apr. 11, 1997, now U.S. Pat. No. 6,040,057 which is herein incorporated in its entirety by reference.
Although polymerized sodium silicate would become completely water insoluble through the application of the methods described in the above described patent application, this investigator felt that simply providing an insoluble form of sodium silicate would not necessarily provide the desired resistance to weathering. This investigator became particularly intrigued by the possibility of incorporating sodium silicate in its liquid state not only into the spaces between cellulosic fibers, but also into the interior of the cells themselves.
It was reasoned that introducing sodium silicate as a liquid into the cellular interiors, and while held in the cellular interior, causing the sodium silicate to polymerize, would change to form to that of a substance, that although it was able to penetrate the cellular structures as a liquid, would not be able to exit from the cellular structures as a solid, becoming effectively trapped within the cellular structures. The result would be the desired fire retardant properties as well as long term moisture resistance.
Although mild use of vacuum and pressure to pressure treat wood is known, what is new and claimed in the present invention, is the use of higher levels of vacuum and higher uses of pressure with the specific intent of forcing chemicals and other substances into the interior of the cells and cellular structures, changing the form of the substances thus introduced, so as the prevent the possibility that such substances would be able to move back out of the cellular structures as a result of other influences such as the leaching action of water.